Questions and controversy continue to swirl around what has been characterized as a rogue geoengineering experiment in international waters off the coast of British Columbia. But whether the action was legal under international law or likely to be effective from a scientific perspective are beginning to become clearer.

Last week, The Guardian newspaper first reported that in July, a retrofitted fishing trawler dispersed 100 tons of iron dust in an ocean eddy about 321 kilometers west of the islands of Haida Gwaii. The iron was intended to foster the growth of phytoplankton and thereby boost the entire marine food chain which it supports, including salmon valued by the indigenous Haida people who live in the area. Such "fertilization" projects have also been touted as a way to soak up atmospheric carbon dioxide and curb global warming.

At this point, answers to the legal questions surrounding the fertilization experiment seem the most clear. The experiment was conducted by the Haida Salmon Restoration Corp., and backed by a California businessman, Russ George. The ETC Group, an environmental watchdog organization, contends that the iron-fertilization scheme was a violation of international law, including the U.N. Convention on Biological Diversity (CBD) and the London convention on dumping of waste at sea, also known as the London Protocol. CBD did adopt two positions discouraging ocean fertilization, notes Edward Parson, a professor of law at the University of California, Los Angeles, School of Law. But these decisions are strictly advisory, and not legally binding, he adds. And while the London Protocol is binding, it only applies to the release of material intended to be dumped as waste, not released as part of a scientific experiment. Even if the quality of the science is dubious, as many ocean experts argue in this case, Parson says because the material was not dumped as waste, "there is no violation under international treaty." Canadian officials, however, are still investigating whether the experiment may have violated Canadian law.